Metabolic syndrome: When and how to intervene
Ob/Gyns are in a position to intervene early enough to make a difference in diabetes and heart disease risk—and intervention does reduce risk.
Several studies have identified dyslipidemia as the key component of metabolic syndrome. That is not to say that other components are unimportant—only that lipid abnormalities appear to have the greatest impact.
In a trial from the Third National Health and Nutrition Examination Study (NHANES III),7 the large dataset that has been studied extensively for this disorder, low HDL cholesterol and high blood pressure in the presence of overt diabetes appeared to account for much of the excess risk associated with metabolic syndrome. In fact, blood pressure, HDL cholesterol, and diabetes—but not metabolic syndrome per se—were significant multivariate predictors of prevalent CHD.7
Twice the risk of myocardial infarction and stroke
Another recent study8 found twice the risk of myocardial infarction and stroke when metabolic syndrome was present.
Investigators used logistic regression to estimate the association of the syndrome as a whole and each of its 5 component conditions separately with a history of myocardial infarction (MI), stroke, and either MI or stroke (MI/stroke).
Metabolic syndrome was significantly related in multivariate analysis to MI (odds ratio [OR], 2.01; 95% confidence interval [CI], 1.53 to 2.64), stroke (OR, 2.16; 95% CI, 1.48 to 3.16), and MI/stroke (OR, 2.05; 95% CI, 1.64 to 2.57).
Among the 5 component conditions of metabolic syndrome, the following were independently and significantly related to MI/stroke8:
- insulin resistance (OR, 1.30; 95% CI, 1.03 to 1.66),
- low HDL cholesterol (OR, 1.35; 95% CI, 1.05 to 1.74),
- hypertension (OR, 1.44; 95% CI, 1.00 to 2.08), and
- high triglycerides (OR, 1.66; 95% CI, 1.20 to 2.30).
With nutritionist counseling, glucose-impaired patients lost weight
Can lifestyle adjustments alone prevent type 2 diabetes to any great extent? Can anything be done to get overweight patients with impaired glucose to stick to a diet and exercise regimen?
Yes to both questions, according to researchers who conducted a randomized, controlled trial3 of lifestyle changes among 522 middle-aged, overweight men (n = 172) and women (n = 350) with impaired glucose tolerance and a mean body mass index of 31.
Chief intervention was nutritionist counseling
Nevertheless, getting the study participants to live healthier was a complex undertaking. The intervention group received individualized counseling to encourage them to:
- reduce their weight by 5% or more
- reduce fat consumption to less than 30%
- limit saturated fat intake to less than 10%
- eat 15 g or more of fiber per 1,000 kcal of intake
- exercise moderately for at least 30 minutes daily
- eat whole-grain products, fruits and vegetables, low-fat dairy products and meat, and vegetable oils rich in monounsaturated fatty acids.
Each person in the intervention group met with a nutritionist 7 times during the first year of the study and every 3 months thereafter. Dietary advice was based on 3-day diaries of food intake, completed quarterly.
Endurance exercise was recommended to increase aerobic capacity and improve cardiorespiratory function. In addition, progressive, individually tailored, circuit-type resistance training was offered to improve muscle strength. During the first year of the study, the rate of participation in these resistance training sessions ranged from 50% to 85%.
A very different picture for controls
In contrast to the individualized attention focused on the intervention group, controls received general oral and written information about diet and exercise at the beginning of the trial and at each annual visit, but no detailed counseling. They also completed a 3-day food diary at the beginning of the study and at each annual visit.
Risk of type 2 diabetes 58% lower
The percentage of patients in the intervention group who achieved a particular goal ranged from 25% (fiber consumption) to 86% (exercise). Net weight loss at the end of the second year was 3.5 ± 5.5 kg in the intervention group versus 0.8 ± 4.4 kg in the control group (P.001 for both comparisons>
While this weight loss was not dramatic, the differences between groups was substantial. For example, individuals who lost at least 5% of their baseline weight had an odds ratio for diabetes of 0.3 (95 percent confidence interval, 0.1 to 0.7).
Over the duration of the trial, the cumulative incidence of type 2 diabetes was 58% lower in the intervention group than in the control group (P.001>3 When women were singled out, the incidence of diabetes was 54% lower in the intervention group than among controls.
The failure to make any changes in lifestyle led to an incidence of diabetes very near the 35% estimate for this high-risk population.
Patients willingly stuck to diet, exercise
The dropout rate was low, and the researchers concluded that patients with impaired glucose tolerance are “willing and able to participate in a demanding intervention program if it is made available to them.”13
